Reality-preserving image encryption assosiated with the chaos and the LCT

A novel scheme on reality-preserving image encryption is proposed in this paper. The chaos function and the linear canonical transform are employed. The unpredictability and initial sensitivity properties of chaotic system are utilized to generate both the scrambling matrix and the masks for encryption. The image is processed in the linear canonical domain via saving half of the spectrum to construct the real encrypted image which is real-valued without data expanding. It can benefit the digital processing of images by electronic computers where speed of computation is important. The key space is large enough to make brute-force attacks infeasible. The robustness with respect to the blind encryption is performed. Simulation results show the validity of the proposed technique.